Earthdog solid hemp martingale collars feature 100% hemp webbing. available in 6 colors and undyed natural. hypoallergenic. unlike nylon and other synthetics, hemp softens with wear making these collars extremely comfortable for your dog and, because they're machine-washable, they're hassle-free for you. all collars are 1" wide small: 8"-14" medium: 14"-20" large: 18"-26"